The invention of artificial cardiac pacemakers, radiofrequency identification devices (RFID), remote keyless systems and similar stand-alone devices represent a large demand for long standing, high capacity batteries that last for years or several tens of years without charge. Primary Li batteries cater to these applications and complement the secondary Li-ion batteries when the recharge of batteries is prohibited or not needed. In a typical battery, the individual components such as electrodes and electrolyte have their functions preset and do not overlap with one another.
The Li—CFx battery system offers one of the best energy densities with up to 7 times the capacity of LiCoO2-based Li-ion system, a conventional Li-ion battery cathode and up to 2 times the capacity of thionyl chloride, the nearest energy dense primary cathode. Even at lower concentrations of fluorine, the Li—CFx system offers more capacity than the Li—MnO2 system. Additionally, the Li—CFx system is extremely stable, offering excellent shelf life (>10 years) and minimal (<10%) self-discharge. A conventional Li—CFx battery uses an inert liquid electrolyte. The solvation process is an indispensable part of the electrochemical reactions that are described by the following equations:xLi+xS→xLi+·S+xe− (Anode, where S stands for solvent)  (1)CFx+xLi+·S+xe−→C(Li+·S−F−)x→C+xLiF+xS (Cathode)  (2)
Limitations of this battery chemistry, such as 1) heat generation during the course of reaction, 2) volume expansion resulting from the crystallization and precipitation of LiF, 3) poor electrode kinetics and low electronic conductivity restricting the performance at high discharge rates, and 4) flammability concerns with organic electrolytes have restricted the widespread application of Li—CFx cells. These limitations are closely linked to the solvation process of Li—CFx batteries. The volume expansion of the cathode could result from the intercalation of solvent into the carbon during discharge coupled with the voids pillared by the LiF crystallization between graphene layers, following discharge. The high enthalpy of crystallization for LiF (26.91 kJ mol−1), results in heat generation during the discharge reaction. A move away from the solvation chemistry would eliminate the volume expansion from solvent intercalation and result in the formation of amorphous LiF, minimizing the heat generation. Thus, the elimination of solvents is expected to be a fundamental improvement in current generation Li—CFx batteries. Solid-state Li-ion conductors offer a step away from the solvation chemistry while offering better mechanical properties, electrochemical and thermal stability. Nanoporous β-Li3PS4 (LPS) has been recently reported as an superb solid electrolyte that is stable with metallic lithium anode.